mzpp and mztext: Preprocessors

Eli Barzilay

The "preprocessor" collection defines two Scheme-based
preprocessors for texts that can have embedded Scheme code. The two
processors share a few features, like several command-line flags and
the fact that embedded Scheme code is case-sensitive by default.

Note that these processors are not intended as preprocessors for
Scheme code, since you have macros to do that.